A micro-lens array screen or lens sheet technology (lenslets or miniature lenses arrayed on a flat sheets) have been in use for almost a century. In a United States patent granted in 1915, W. Hess used a corduroy-like vertical going lenticules that refract only in the horizontal direction. Hess also described a means to photograph left and right images and to then combine them optically into an interdigitated (slicing into strips and alternating the strips of left and right perspectives) micro-lens array stereogram. FIG. 1A explains how the Hess and similar systems work. The eyes of the viewer are indicated at R and L.
FIG. 1B illustrates a lenticular mask placed over a display that generates nine fields of view. Each lenticule in the lenticular mask covers nine vertical columns of pixels. In every field of view, one eye can see only one column of pixels. If we arrange nine digital cameras in a row, take nine pictures and display the n-th pixel column of the image taken with the first camera in the first column of pixels under the lenticule, the same pixel column taken with the second camera in the second column of pixels and so on, we can produce lenticular stereogram on the screen. Moving laterally across a viewing zone gives the look-around effect because each eye is seeing different images as a stereo pair. Moving out of one viewing zone into the next zone repeats the exact same perspective progression. Within a viewing zone, a viewer may see any two of nine views depending upon where you the viewer is located. Two views (e.g., views 1 and 4 or views 6 and 8) make a stereo pair.
Each resulting 3D image has one-ninth the resolution of the total horizontal resolution and the same vertical resolution. This unequal resolution in the x and y directions negatively impacts visual perception and causes an undesirable pattern composed of small dots (optical moiré) to appear in the image.
A more recent technique equalizes resolution in the x and y directions by using a different pixel layout of the display. In particular, this technique arranges the views in a tiled pattern of rectangles three by three, as illustrated in FIG. 1C. The micro-lens directs each of the sub-pixels into its viewing zone. Each 3D image has one-ninth the resolution of the total resolution (one third in each direction).